The purpose of this research study is to learn how people distribute their visual attention when looking at objects nearby versus far away, and why vision may become distracted at near versus far distances.

Visual distraction is a problem that more often occurs people who have suffered strokes than in the general population. Problems of visual attention generally appear immediately following a stroke, and may impair driving and other functions. While it is thought that there is a natural course of improvement over time, little is known about how this improvement occurs. Some studies suggest that recovery is only partial, meaning certain aspects of visual attention may improve while other aspects remain but escape notice.

The purpose of this study is to examine the effect of stroke on a person's visual attention when looking at objects nearby versus far away, and to learn why a person's visual attention may become more distracted at near versus far distances. The purpose of this study is also to understand how modeled interventions, such as eye patching or prism goggles, affect impairment measures of visual attention.

After an initial screening (including attention, thinking, memory, and visual judgment tests), participants will be given a neurological examination. Participants may be asked to perform visual tasks while wearing an eye patch or prism goggles. Next, they will be asked to perform a line bisection task by looking at lines on a video screen either at close or far distances and, using a laser pointer, marking the center of the lines as they appear on-screen. Participants may be asked to perform other, similar visual tasks as well.

Duration of the study for participants varies, ranging from 1 or 2 sessions totaling approximately 2 hours to multiple sessions spanning a year.

Research from this study may help researchers better understand problems associated with stroke and may lead to therapies designed to promote improved visual attention.

Inclusion Criteria:

• The subject has a history of stroke.
• The subject is 18 to 100 years old.
• The subject is able to give Informed consent.
• The subject is post-Stroke with left-hemisphere injury and has no spatial neglect (no attentional imbalance).
• The subject is post-stroke with right hemisphere damage and has spatial neglect (attentional imbalance).
• Healthy subject with no brain injury.
• The subject is post stroke and has hemianopia (a "visual field cut").
• The subject is able and willing to comply with the study protocol, including availability for all scheduled clinic visits.

Exclusion Criteria:

• Subjects with brain tumors, head injury with loss of consciousness, visual disorders other than corrected near or far-sightedness, history of learning disabilities, dementia or Alzheimer's Disease.

Persons who have had a stroke. Also, healthy volunteers.